The use of polytetrafluoroethylene (PTFE) with fillers is known in the manufacture of seals, bearings, and like articles, all of which have a working surface that rubs against another surface moving relative thereto.
For example, a liquid chromatography pump manufactured by Waters Associates, Inc. (and described in copending application Ser. No. 10,686), currently uses a seal composed of PTFE filled with glass fibers. It is also known to make bearings from PTFE filled with fluorinated graphite.